TMNT 2012 and SVTFOE: Half Mutants, Half Mewnans
by Marialine
Summary: Leo gets separated from his brothers and ends up in Mewni then both he and the Queen Moon fall for each other. Many years later, their twin children get into trouble so they sent into them to the Earth dimension. While the two are there, Leo finds out something about his old family that will change their lives forever.


_**Ch. 1- The Ninja Turtle And The Monster Queen 1**_

 **A/N Oh, BTW, in this crossover AU, Eclipsa did marry a monster but she wasn't crystallized during her time for bad things yet she told Rhombulus to crystallize her so that she can live in the future to see a new Mewni. But her daughter Meteora was the queen so all their descendants, including Moon, are half-Mewnans and half-monsters yet they will still go through Mewberty.**

 **Also, this is Season 4 in TMNT 2012 yet Samurai Arc has occurred already.**

 **ENJOY!**

* * *

 _ **Leo's POV:**_

" MIKEY! NO!" I screamed as loud as I can but it was too late.

Super Shredder stabbed both of the blades of his gauntlets through my little brother's plastron and out of his shell. His high-pitched screams rang through me and my other brothers' ear lobes but I couldn't bear it. Out of my anger, I took Donnie's teleportation device and smashed it on the floor.

" Leo!" Donnie yelled." Why did you do that?! It's gonna…"

Suddenly, a portal ripped open and then the five of us got sucked into it's core. Raph and Donnie took hold of our little brother's bleeding body while I took care of that cold-hearted monster. I took out both of my katanas and slashed Shredder so much until I was finally sure he was dead. Unfortunately, he was able to slash both my other brothers and it got me so mad that I finished him for good. I gave him a good kick before he dissolved into nothingness. I panted and turned to my brothers; Raph holding tight to his wounded waist and Donnie clutching to our little brother with tears, not paying attention to his bleeding arm. I was about to go to my genius brother when he got caught in a portal and disappeared.

" Donnie!" Raph cried out but soon, he was caught in a portal and also disappeared.

" Raph!" I screamed as the tears flowing down my cheeks went up while I fell down deeper until I found the end of the portal.

It teleported me to a forest and I landed on a thorn bush.

Ouch! That actually hurt.

I struggled out of the said bush and brushed off the leaves from my skin before turning to look at the field in front of me. I gasped to see tents and different types of strange creatures in battle armors with lots of weapons. I saw a tall lizard humanoid with 2 skull faces as his shoulder pads. He was with 2 other monsters and was walking towards the forest. I gulped and ran to the thorn bush again.

Okay, bad idea. The thorns still pricked and hurt me but it was still a safe place so oh well.

Anyway, I panted and cold sweat dropped down my head as I heard footsteps going closer to where I was hiding. I was relieved, though, when I heard them going away but I was so relieved that I couldn't hold in a sigh.

" Did you hear that?"

" Yeah, general. It came from that thorn bush!"

" Maybe there's a knight from the castle in there! We have to kill him!"

Suddenly, my heart kept on beating fast as I heard their footsteps come closer and closer. Then, the bush was parted and I froze.

" Oh. And what do we have here?"

I turned to look up at the lizard humanoid closely, his coal black confident eyes staring straight at my frightened midnight blue ones.

" Well, hello there," he seemed to be polite." Who and what might you be, young fellow?"

" L-Leonardo," I stuttered as I tried not to shiver too much." I-I'm a ninja turtle,"

" Hmm, I can see that. And to who do you work for?"

I got confused." Um, no one. I work for on my own now but I can fight,"

He took a look at my katanas and then grinned.

" Well, then, would you like to work for me? My team is the lizards yet we'd need a great swordsman to face the Mewnans and monsters that fight for Mewni. We lizards are the rogue monsters and we fight to be better than the Mewnans,"

I gave his offer a heavy thought as I bit my lip.

Should I join him? I mean, all my brothers are most likely to be dead by now so what else have I got to lose?

I took a deep breath and nodded with a serious face.

" Good!" the lizard shook my hand with his grin." My name is Toffee but you have to call me General Toffee cause now, I'm your new general,"

" Yes, General Toffee," I replied with a nod.

" Good! Now, let's go back to base camp,"

I nodded then followed right behind them.

* * *

 _ **Narrator's POV:**_

The lizards ran away in fright after the finger of their general couldn't regenerate anymore. Toffee got pissed off then he brushed off the dust before joining his army on their cowardly retreat. Queen Moon Butterfly sighed in relief as River Johanson ran over to her on his horse and gave her a hug to congratulate her.

" You did it, Queen Moon!" River cheered." You chased away those rogue monsters!"

Moon smiled and hugged back but frowned when the Magic High Commission came to them with not-so-satisfied faces.

" What did you do?" Rhombulus demanded, folding his snake arms.

" I did my job!" Moon confidentially shouted." And I will continue to do my job and hunt down those rogue monsters! Now, are there any questions?"

Her shout made the rest of the Magic High Commission shut their mouths in fear, much to Moon's satisfaction.

" I didn't think so," she began to walk off with the commission giving her a path to walk on.

Suddenly, Hekapoo noticed one of the tents making a lot of racket so she had to inform the teenage queen.

" Um, your majesty," she called out, making the queen turn to face her in curiosity." I think there's still a rogue monster inside that tent! Listen!"

Moon gasped when she heard the same racket that Hekapoo heard so she went towards the tent with two guards beside her.

* * *

" Damn myself for trusting Toffee and teaming up with him and his stupid group!" Leo cursed as he hit a bent sword with a wooden hammer repeatedly to make it straight again." What was I even thinking?! I should've known he was a killer! Those skull faces are total evidences!"

You see, Leo had been out with the other lizard monsters to see Queen Moon enter their camp when he went inside one of the tents to get a spare sword. As he did, he was shocked to find out that Toffee had killed many innocent Mewnans and monsters. He got scared and mad that he took lots of broken weapons and fixed them with the hammer to let his anger out, not knowing what was happening outside.

Suddenly, Leo froze when he heard footsteps coming towards the tent and he got so scared that he grabbed all the swords and kunais he fixed and crouched down behind a wooden pole. He kept on taking in deep breaths as the tent was parted open.

" Hello? Anyone in here?"

The voice sounded a bit serious but also curious and it was clearly heard even if it was in a female British accent. Leo felt a sweat go down his face as he started to pant faster.

" Guards, search the rest of the other tents. I've got this one all under control,"

" Yes, your majesty,"

Two heavy footsteps walked away, making Leo sigh in relief yet he froze again when the female took a few steps towards him.

" Hello? I know you're here so just come out,"

He was shivering in fear and felt his heart stop when he felt something cold and glowing behind his head.

" Don't move."

With that, Leo dropped his all of his weapons and fainted. Moon looked at him with wide eyes before freaking out, nearly dropping her wand in the process.

" Oh my gosh! I killed him!" she cried out.

She sighed in relief, though, when she noticed that Leo was still breathing so she called out the guards to carry the blue clad turtle out of the tent. When he was brought out and showed to the Magic High Commission, however, they all had the strange ideas.

" He's a monster!" Mina Loveberry cried out, transforming to her giant-like form." We should destroy him immediately!"

" Now, hold on!" Moon opposed as she defended Leo." Let's not jump into conclusions,"

" Mina's right," Omnitraxus Prime told the young queen." He's with the army so he must be one of the rogue monsters!"

" But he's not a lizard!" Hekapoo pointed out." He's a turtle! Maybe he was just found by the general,"

" Probably," Rhombulus thought for a while." but how would we know that? He's unconscious!"

Lekmet yelled out a suggestion to Rhombulus in his goat language and the diamond-headed creature nodded in agreement.

" That's a good idea!" Rhombulus turned to the others." Hey, guys, why not just lock up the turtle until he wakes up? Then, we'll put him on trial to prove if he's guilty or not!"

" WHAT?!" Moon gasped in shock but the Magic High Commission didn't seem to hear her out as they agreed with the idea.

" Great idea," Omnitraxus Prime nodded his skeleton head from inside his galaxy-themed crystal ball.

" Guards, take him to the palace dungeon and make sure he doesn't escape!" Hekapoo ordered and the guards did as they were told.

All Moon could do was stare at the Magic High Commission and Mina as they followed behind the guards solemnly. The young queen was so angry that she was ignored that she suddenly made one of her arms turn into a monster one with her blue eyes turning into golden monster ones. When she realized what she did, it shocked her so much that she yelped.

" Oh no!" she rubbed her normal Mewnan arm against her monster one in panic." Not again! I have to calm down! Calm down, Moon!"

To her relief, her monster arm turned back to normal and so did her eyes. She sighed before hopping on her pet and heading back to the palace.

* * *

Leo woke up with a painful groan as his eyes slowly turned from blurry to clear.

" Ugh, what happened?" he still felt weak as he struggled to get up.

His eyes popped open, however, when he realized he couldn't get up to sit so he turned his head to see both of his wrists in shackles tied and connected to the back wall with chains. He tried all his might until he was able to sit up yet when he tried to stand, he realized that the chains could only go so far so he groaned in defeat and just sat down, trying to think of a way to get out of there.

 _Hmm, shackles and chains around my wrists and even around my neck to chain me to this stupid back wall?_ he thought. _Welp, I'm so dead if I can't get out of here._

All of a sudden, the dungeon door opened and he looked up to hear the voice he heard earlier along with another one.

" He's a monster! He should be killed already!"

" Now, Mina, as you remember, my ancestors and I have been half-monsters and half-Mewnans for many years, ever since Meteora was born. So, please, respect the monsters that are innocent,"

" That's not the point, your majesty! We don't know if he's innocent or not!"

" If found guilty, it is still up to the Magic High Commission on what to do with him. Either to crystallize him or to destroy him,"

" I vote for destroying him! One hundred percent!"

" Mina, go to the trial room with the Magic High Commission but you cannot take place in the Trial by Box, alright?"

" Ugh, fine!"

With that, Mina walked off and Moon walked into the dungeon cell, pointing her wand at the captured turtle just in case.

" Hello, prisoner," she greeted in a serious expression.

Leo stared at the glowing wand with fear but tried his best not to show it.

" Uh, hi," he greeted back with a slight smile and a little wave." Hello, Queen…?"

Moon blinked at him in shock as she slowly faced her wand down from his face.

" Moon Butterfly. Queen Moon Butterfly of the kingdom of Mewni but you can just call me Queen Moon. And you are?"

" Hamato Leonardo. I'm a mutant ninja turtle of Earth. You can just call me Leo,"

Moon got confused." Mutant? What does that mean?"

" It means I'm half-turtle and half-human so my race is called a mutant but it simply means that I'm a combination of 2 or more DNAs,"

" Oh,"

Moon looked at her wand and went down to memory lane. Leo, on the other hand, bit his lip, feeling good that the conversation was starting off better than he thought it would be as he turned his head to the cell window.

" So, this place is called Mewni?"

Moon looked up at him as she was snapped out from her trance.

" Um, yes. And I'm ruling the whole kingdom,"

Leo turned to her again in surprise.

" You? But you're just a kid!"

" Hey! I'm about 14!"

Leo was feeling bad that their conversation was turning to the worst but he had to fight back.

" Still younger than me. I'm about 15-16 years old!"

" So?! It wasn't my choice to be queen at this age!"

" Then how are you queen?!"

" TOFFEE KILLED MY MOTHER!"

Leo's eyes widened as Moon turned away with tears at the sides of her eyes. There was a moment of silence before Leo spoke up.

" Toffee killed your mother? But, why would he do that?"

Moon wiped the tears off her eyes and turned back, clutching her wand tightly.

" Toffee rules the rogue monsters, especially the Lizards, since they wanted monsters to have greater rights than the local Mewnans,"

Leo's eyes widened again." Is that the reason why he needed me as a great swordsman to fight?"

Moon gasped." He hired you?"

" Yes, he did,"

" Why did you accept?"

Leo sighed." I-I had no other choice, honestly,"

" What do you mean?"

" I mean, I was lost in the forest after I fell from a portal when he found me and offered me a job,"

" I still don't understand why you'd accepted. What about your family?"

Leo turned away from her with tears starting to appear in his eyes.

" I-I don't have any family anymore,"

Moon's eyes widened in hurt as she sat next to the turtle.

" W-What happened to your old family?"

" T-They were killed," Leo sounded very cold." Well, at least, my three younger brothers were killed. I don't know with my father and half-sister, though, but I'm pretty sure our enemy's henchmen killed them off already,"

Moon felt guilty for the troubles that the older turtle was going through so she rubbed his shell in comfort.

" I-I'm sorry for your family, Leo,"

Leo turned back to her but his eyes widened when he noticed that there was something strange.

" Um, thanks but, your majesty, uh, are you alright?"

" What do you mean?"

" Your arm…"

Moon's eyes widened to see her arm turned into a monster one so she rubbed it with her normal arm until she saw herself in a huge glass shard. She screamed to see her eyes turned into golden monster ones while her demon tail had appeared from a hole from her skirt.

" Oh dear!" she cried out, backing up and turning her head away from Leo with her face red in shame and possible fear." Oh no! I'm so sorry! It's happening again!"

" What's happening?" Leo also got fearful." Your majesty, what's going on with you?"

Moon sighed." Well, you see, my great ancestor, Eclipsa Butterfly, divorced her Mewnan husband and married a monster instead, ending the huge fight and battle between the Mewnans and the monsters forever. Their only daughter, Meteora, was a half-monster and a half-Mewnan baby so all of her descendants, me included, for her half-monster DNA. When I'm upset, hurt and/or stressed out, my, um, monster side starts to show and this happens to me,"

She pointed to her arm, eyes and tail. Leo nodded in understanding but Moon still sunk into depression.

" Hey, hey, it's okay," Leo tried to calm her down as he rubbed her back in comfort.

" No, it's not!" Moon started crying even more." No one is going to like a half-monster queen like me!"

" Well, all of your half-monster ancestors were able to get married and have children. I mean, your mother, Queen…?"

" Comet. Queen Comet Butterfly,"

" Right, right. I mean, your mother, Queen Comet, was able to find your father and have you as a daughter!"

" Dad was also killed. Many have suspicions that Mom killed him but I don't believe it,"

Leo coughed in disturbance but kept on talking to comfort her.

" Well, um, anyway, your mother was still able to get a husband and that's what matters. If she can get someone to adore you, so can you,"

Moon turned to him and smiled, letting her monster features disappear and allowing her to look at him with her normal blue eyes.

" That's…true," she gave him a hug, making him blush." Thank you, Leo. You sure know how to make a half-monster feel better,"

Leo smiled and hugged back then when they parted, Moon stood up and looked serious.

" Um, Leo," she told him." later, you are going to be put on trial,"

" Trial?!" Leo suddenly got really worried." Why?! I didn't do anything wrong!"

" Well, we found you at the tent of the lizards so the Magic High Commission thought that you are an ally of them,"

" The what?"

" The Magic High Commission is a group of powerful magical beings who act as guardians of magic in the universe, which is composed of four different beings; Hekapoo, Omnitraxus Prime, Lekmet, and lastly, Rhombulus. I'm included in it with my guide Glossaryck,"

" Oh, okay. So, what's the trial?"

" I'm not suppose to tell you but since I trust you and I know you aren't guilty, I'll tell you. The trial is Trial by Box, meaning we're going to use the Box of Truth, which will judge you. We must put our pinky on the box opening to pinky swear that we'll tell the truth no matter what or else we'll have to face the consequences of the box. Now, each of us we'll have to ask you a question and you have to tell the truth with explanation. Remember, tell the TRUTH WITH YOUR OWN EXPLANATION! Or else they will not believe you then at the end of the trial, we'll see if you're guilty or not,"

Leo nodded, feeling very nervous now as Moon turned around and left him inside. He sighed and hugged his knees while looking down at his feet.

" Oh, sewer apples, I'm so dead…"

Two guards fetched Leo out of the dungeon cell and he still had two metal cuffs on as he was entered to the trial room. The Magic High Commission were already on their seats, with Moon staring at her new friend in worry as Leo stood in the trial stand. The said turtle in blue got a lump of fear in his throat but he tried to swallow it in anyway to appear confident.

" And now," Moon did her hardest to sound not afraid." we will start the Trial by Box. We must all do a swear to the box to start,"

She held out the box and each of the members of the commission did a pinky swear (well, Rhombulus used one of his arms' snake tongues) then Leo did the pinky swear before the trial started.

" Lekmet, you will start us off this time," Moon turned to the high chancellor, who nodded.

Lekmet said lots of things in his goat language, which made Leo so confused that he just stared.

" Exhibit A," the box said, meaning that it understood what the goat chancellor just said as it flashed it's light towards the turtle in blue, who yelped in shock.

" Um, not to be rude but what did he just ask?" Leo asked.

" Oh," Rhombulus realized in a bit of a shock." you can't understand goat language? Well, Lekmet asked who are you and what kind of monster are you,"

 _Remember, tell the TRUTH WITH YOUR OWN EXPLANATION!_

Leo took a deep breath and then answered," First of all, I'm Hamato Leonardo, a ninja turtle from the Earth dimension. Secondly, I'm not a monster. I'm a mutant, a creature that's a combination of 2 or more DNAs,"

" Truth!" the box exclaimed.

Moon looked over at Hekapoo and sighed in relief to see the scissors enforcer putting a check on the good column.

" Hekapoo, you're next," the teen queen said.

" Okay," Hekapoo cleared her throat before asking," So, Hamato Leonardo, is it true that you worked for Toffee and his Lizard clan of rogue monsters?"

" Exhibit B," the box said, showing a hologram of Toffee and his clan's symbol.

" Yes, I did," Leo replied with no hesitation." Toffee gave me an offer to work for him and his crew as a great swordsman. My family was already killed by our enemy so I had no other choice but to work for someone to help myself not lose my sanity,"

" Truth again!" the box cried out.

The horned humanoid seemed to understand as she nodded and placed another check on the good column, much to the queen's delight.

" I'll go next," Omnitraxus Prime gave out a little glare." Leonardo, is it true that you used you katanas to kill someone and that's why your blades were bloody?"

" Exhibit C," the box spoke up and it showed the hologram of his bloody katanas.

Leo looked behind him to see that his katanas were no longer there, pissing him off but he had to control his rage to answer.

" Yes, I did use them to kill someone," he replied." That's why it's bloody. After my family's enemy killed my brothers, I used them to stab him very hard then I gave him a hard kick to finish him off,"

" This turtle's an honest child!" the box seemed pleased.

" Oh, by the way," Leo wasn't done speaking." You guys should never have taken a ninja's katanas, even it meant that you needed it for an accusation against me. Those were given to me by my father and they're really important to me,"

" TRUTH AGAIN!" the box seemed excited." This young one is amazingly honest,"

" We're sorry, Leonardo," Moon apologized, much to the rest of the commission's shock." Don't worry, though. Your katanas are clean now and kept in a safe place,"

The ninja smiled, making the queen blush with a smile back as she also sighed in relief when Hekapoo placed a 3rd check below the good column. She cleared her threat before speaking again.

" Rhombulus, you're up,"

" Oh, right," Rhombulus cleared his throat too before asking," Hamato Leonardo, have you eaten or killed any innocent creature?"

" Exhibit D!" the box cried out as he took out a hologram of a cartoon version of the blue clad turtle with a big mouth and sharp teeth.

That question disturbed Leo but he gulped in a lump of disgust and then answered," First of all, that is one of the most disturbing questions anyone has ever asked me in my entire life. Secondly, no, I have not eaten nor killed anybody who is innocent. Only villains like my family's enemy, the Shredder,"

" The honesty train is on a roll tonight, people!" the box said in an excited tone.

Hekapoo took note of that and placed another check below the good column. Moon took a deep breath then turned to Glosssaryck to motion him to ask next.

" Alright," Glossaryck floated to the ninja turtle and asked," Hey, Leon, have you got any experience with any magic before?"

" Exhibit E," the box showed a hologram of the royal wand.

Leo looked at it closely then responded," Firstly, my nickname is Leo, not Leon. Second of all, not really with an actual wand. I mean, I have seen my future friend Renet use a time scepter to go through the past, present and future but I haven't actually tried wielding a magic wand,"

" Go go, the honest train!" the box cheered.

Moon smiled as Hekapoo placed another check below the good column then the teenage queen took a deep breath and stood up from her seat.

" Leo," she said in the boldest voice she can let out." this is your final question; are you sorry for joining Toffee?"

" Yes," Leo replied with not a single miss of a beat." I am sorry. When I met him, he seemed nice but soon, I found out that he killed lots of innocent people but it was too late when I found out. I couldn't fight him so I hid myself like a coward,"

" Truth and that's final!" the box cried out before turning back into an actual box and landing on Moon's palm.

" Welp, that settles that," Hekapoo rolled the scroll that she used in her hand." Hamato Leonardo is found innocent and won't be crystallized nor killed,"

" WHAT?!" Mina seemed angry as she stomped to the Magic High Commission." WHY?! HE IS A MONSTER! HE WORKED FOR THE LIZARDS AND TOFFEE! HE NEEDS TO BE KILLED!"

She grew into her large size and grabbed Leo, who struggled and shivered in fear. Moon got mad and then her arms and legs turned into monster ones with her tail suddenly appearing from her skirt and her eyes turning monster gold.

" Leave him be, Mina!" the monster queen demanded before jumping to the giant warrior and giving her a hard punch.

Mina was sent back to the wall, turning into her normal self again while Leo screamed as he fell so Moon transformed back to her normal full Mewnan form and grabbed her wand.

(OKAY, I'M JUST MAKING UP MOST OF THE SPELLS RIGHT NOW)

" Bed Sub-transform!" she chanted and with a blast, the trial stand transformed into a bed, which was able to make Leo's fall softer than he'd expect.

Leo, on the other hand, panted for his life as he placed a hand on his chest and sighed. Moon ran to him and helped him on his feet.

" Are you alright, Leo?" she asked.

" Yeah," he replied." A little scared and mostly traumatized but still good enough to have sanity,"

" Oh thank goodness,"

Moon turned to Mina, who stood from the broken wall, and the teen queen pointed her glowing wand at the other female.

" Leave now," she threatened angrily." Or else face the consequences,"

" Fine!" Mina stomped out of the room and left the castle.

Moon sighed in relief then when she turned around, she smiled to see the Magic High Commission letting Leo out of the handcuffs.

" Now," Omnitraxus Prime started to say." since you are from the dimension Earth, we will sent you back,"

Leo's expression turned from happy to sad.

" But why?" he folded his arms as he said so." What's the use of going back? I have no family to go back to,"

" Oh right," Moon walked over to the ninja and placed a hand on his shoulder." We can't just send him back to Earth and return to a lonely home. Leo, you will stay here with us on Mewni and you can be like a knight here to protect us from the rogue monsters. Now, how does that sound?"

Leo smiled and gave a warm hug to the queen, who blushed very deeply in response with her cheek marks turning red.

" Thank you, your majesty," he said after pulling away." I'll redeem my honor in this and I won't fail you, Queen Moon,"

Moon coughed a bit because of her embarrassed face then smiled as the ninja turtle cheered.

 _But that was just the beginning…_


End file.
